Rod

I recently bought a new computer. I reinstalled Pixillion to the new computer and activated it using my purchased serial. I converted some images to be uploaded to my online gallery hosted by Pixieset. Pixieset gave me an error saying that the files I uploaded were not the correct format. I have been using Pixillion and Pixieset for several years and now Pixieset will not accept files converted using Pixillion. I tested this by uploading images not converted using Pixillion and there were no problems. What am I doing wrong here? This started happening when I got my new Imac and using Pixillion on it.